The Clinical core Facility will serve the needs of several projects in the overall grant. The core's major role will be to enroll patients in the clinical projects and to obtain historical information and clinical specimens from the patients for these projects. The core will consist of a director, a co-director, and four nurse practitioners. The core will be based in the Bell Flower STD Clinic but will use the Adolescent Clinics (located at 5 sites in the Indianapolis metropolitan area), the Obstetrics Clinic and Gynecology Clinic at Regenstrief Outpatient Clinic and the Infertility Clinic at Indiana University Hospital.